As hardware for reproducing and storing high resolution or high quality image content is being developed and supplied, a need for a video codec for effectively encoding or decoding the high resolution or high quality image content is increasing. According to a video codec of the related art, a video is encoded according to a limited encoding method based on coding units of a tree structure.
Image data of a spatial domain is transformed into coefficients of a frequency domain via frequency transformation. According to a video codec, an image is split into blocks of a predetermined size, discrete cosine transformation (DCT) is performed on each block, and frequency coefficients are encoded in block units, for rapid calculation of frequency transformation. Compared with image data of a spatial domain, coefficients of a frequency domain are easily compressed. In particular, since an image pixel value of a spatial domain is expressed according to a prediction error via inter prediction or intra prediction of a video codec, when frequency transformation is performed on the prediction error, a large amount of data may be transformed to 0. According to a video codec, an amount of data may be reduced by replacing data that is consecutively and repeatedly generated with small-sized data.
An encoding or decoding method that generates a merge candidate list is used to determine a prediction mode for compressing a current prediction unit included in a current coding unit. The merge candidate list may include a temporal merging candidate, a spatial merging candidate, a view synthesis prediction (VSP) merging candidate, and the like.
According to the related art, view synthesis prediction is used to determine whether blocks corresponding to all spatial merging candidates neighboring a current prediction unit have been encoded, so as to add a view synthesis prediction merging candidate to a merge candidate list. However, since the process of generating the merge candidate list requires an unnecessary calculation, image compression efficiency may be deteriorated.